The Frightened Inn-Keeper (The Saint TV Series)

Plot
The Saint is summoned to a remote inn in Cornwall by Julia Jeffroll, although, when he arrives, it is clear that her father, the inn-keeper, though telling him that there is nothing wrong, is actually very scared, especially of three male guests at his inn. Julia tells the Saint that she hears strange noises at night and has overheard the men boast about coming into money very soon. Then the Saint discovers that there is a tunnel being built in the cellar with an underground rail-track. He decides to investigate.

Origin
This episode was adapted from the novella "The Case of the Frightened Innkeeper" from the 1934 book The Saint Goes On.